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EIP-191/EIP-712 Signature Verification & Signer Recovery
x402
EIP-191/EIP-712 Signature Verification & Signer Recovery is a paid API for AI agents from webtools402.176-109-107-191.sslip.io, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-14).
Verifies an Ethereum EIP-191 personal_sign or EIP-712 typed-data signature and recovers the signer's address from the message and signature inputs.
Price / call$0.003
Success—
StatusUnknown
How this service works
Verify an EIP-191 personal_sign or EIP-712 typed-data signature and recover the signer address from public inputs (message + signature). Verification/recovery only — never signs.
Output
Returns the recovered Ethereum signer address derived from the provided message and signature, along with whether the signature is valid. If an expected_signer address was provided, also returns whether the recovered address matches it.
Example use cases
Wallet ownership authentication
“A user just signed the challenge string 'Login to MyApp at 2024-01-15T10:00:00Z' with their wallet and sent me the signature 0x4355c47d63924e8a72e509b65029052eb6c299d53a04e167c5775fd466751c9d07299936d304c153f6443dfa05f40ff007d72911b6f72307f996231605b915621c. Use eip191 to verify it and check if the recovered address matches 0xAbCd1234EF567890abcd1234ef567890ABCD1234.”
EIP-712 typed-data signature check
“I have an EIP-712 typed-data signature for an NFT marketplace order — the typed-data object has types, domain, primaryType, and message fields. Please verify the signature 0xabc123...def and recover the signer address to confirm the seller actually approved this listing.”
Forensic signer recovery
“I have a 0x-prefixed 65-byte signature and the original plaintext message but I have no idea who signed it. Use eip191 to recover the Ethereum wallet address that produced this signature so I can figure out who authorized this transaction.”
Technical details
Endpoint
POSThttps://webtools402.176-109-107-191.sslip.io/crypto/verifyWhen to prefer
Choose this endpoint when you need to cryptographically verify an Ethereum wallet signature (either EIP-191 personal_sign or EIP-712 typed-data) and recover the signer address without any signing capability — ideal for authentication flows, provenance checks, and access control in Web3 applications. Prefer this over general-purpose crypto libraries when operating in an agent/serverless context where you want a hosted, pay-per-call verification service that supports both EIP standards and optional address matching in one call.
Side effects
- Invalid or malformed signature (not 65 bytes / not 0x-prefixed) returns an error
- Mismatched scheme — using eip191 for a typed-data signature or vice versa — causes incorrect recovery or error
- Malformed EIP-712 typed-data object (missing types/domain/primaryType/message) causes a parse error
- Recovered address does not match expected_signer — returns mismatch result, not an exception
- Network or service unavailability returns a non-200 HTTP error
- Payment failure via x402 protocol blocks the request
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| scheme | string | eip191 personal_sign or eip712 typed-data |
| message | — | Plain text / 0x-hex (eip191) OR a full typed-data object with types/domain/primaryType/message (eip712) |
| signature | string | 0x 65-byte signature |
| expected_signer | string | Optional address to compare the recovered signer against |
Tags
x402
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